"I think anyone who was proclaiming victory a couple of months ago was premature," said Rep. Daniel Kildee, D-Mich., a leading member of the Democratic Congressional Campaign Committee. "I think the president's standing obviously has some impact."

In a Gallup poll released last week, Trump's approval rating held firm at 42 percent, his highest weekly average in a year. Democrats were banking on Trump's unpopularity with voters dragging down other GOP candidates, but that might not be the case.

"His presentation leaves a lot of people lacking," Keith Lowry, chairman of the Jefferson County Republican Executive Committee in West Virginia, said of Trump. "And they don't necessarily agree with his brash techniques or the way he tweets a lot. But the essence and the substance of the man — you just can't argue with the accomplishments."

Democrats hope issues like healthcare, veterans, and local concerns will overcome party loyalties.

"Anyone who's counting on a national wave to carry her into office isn't much of a candidate," said Rep. Matthew Cartwright, D-Pa., a candidate in a district that Trump won by 10 points in 2016. "You've got to run your own race and you have to be your own person."

The upcoming midterm elections might not hand Democrats a congressional majority, according to The Washington Post, because President Donald Trump’s approval ratings are rising and Republicans are showing a strong turnout in primaries.